260 ALASKAN GLACIER STUDIES Map 6, as well as two sets of transit readings upon the ice front from stations listed below, which are readily accessible and should be revisited in years to come to determine the behavior of the glacier, whose advance from 1909 and 1910 is shown by Fig. SO, based FIG. SO. TBIANGTJLAIION ON FBONT OF COLUMBIA GLACIER SHOWING ADVANCE FBOM 1909 TO 1910. upon these transit readings. Stations B and C are close to the plane table stations occupied by Gilbert in 1899, and are each within a few feet of photographic stations H and I, see Map 6.